Understanding the Function of Brain Networks through Neuromodulation

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Together with Dr. Christine Tipper, Dr. Todd Woodward aims to better understand the role of brain networks in cognition and behaviour and to explore how modulation of brain networks might improve recovery in people with schizophrenia.

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Our current 256 channel electroencephalography (EEG) system provides an exceptional measure of brain network activity, providing a temporal resolution that is three orders of magnitude finer than fMRI. Our recent work has made it possible to map out 3-4 times as many brain networks as fMRI, revealing transient brain processes that interact dynamically, thus portraying functional brain network configurations. The CNoS Lab is one of the first in the world to have successfully developed methods of measuring networks of combined frequencies of oscillation during a range of tasks. The addition of a Geodesic Transcranial Electrical Neuromodulation (GTEN) system will allow our lab to move forward with even more innovative research on brain networks and schizophrenia, using a method known as transcranial Alternating Current Stimulation (tACS).

What is tACS?:

tACS is a safe and non-invasive neuromodulatory technique that uses an oscillating sinusoidal current to interact with the brain’s natural cortical oscillations. This safe technique uses a weak electrical current (~ 0.025-0.1 mA/cm2) applied to the scalp. This low-intensity current does not directly alter brain activity, but instead temporarily changes the excitability of targeted cortical regions, allowing the function of brain network activities to be studied scientifically. The current used in tACS is often imperceptible, but may be experienced as faint tingling sensations on the scalp. This safe, painless, non-invasive brain stimulation technology holds great promise as a therapeutic application for neurocognitive, neurological, and neuropsychiatric brain health conditions.

What is the GTEN system?:

Geodesic Transcranial Electrical Neuromodulation (GTEN) provides the latest advance in neuromodulation technology, with the capacity to deliver small amounts of highly specific patterns of alternating electric current across the entire 256-channel electrode array in order to excite or suppress the activity of neurons in specific areas of the brain. This new GTEN hardware will compliment our state-of-the-art high-density EEG system and allow for testing of hypotheses about the function of specific brain networks organized by frequency-specific neuronal oscillatory activity. As well, the GTEN enables concurrent EEG measurement and stimulation, enabling a novel means of directly assessing the effects of electrical stimulation on brain activity. The results we have achieved thus far [1,2,3] suggest that a pre-treatment with neuromodulation should improve performance on cognitive tasks in persons with schizophrenia.

How to participate:

The Cognitive Neuroscience of Schizophrenia Lab is currently recruiting healthy controls to participate in studies to better understand brain networks. These studies will aid the study investigators in developing protocols to: 1) influence network-level brain function in a precisely targeted manner, 2) directly assess the effects of particular neuromodulation sequences on cognitive, behavioural, and neural function, and 3) test specific causal hypotheses about the role of particular brain network configurations in specific aspects of cognition and behaviour.